libstdc++-v3/config/locale/dragonfly/codecvt_members.cc

   1 // std::codecvt implementation details, DragonFly version -*- C++ -*-
   2
   3 // Copyright (C) 2015-2020 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 //
  26 // ISO C++ 14882: 22.2.1.5 - Template class codecvt
  27 //
  28
  29 // Written by Benjamin Kosnik <bkoz@redhat.com>
  30 // Modified for DragonFly by John Marino <gnugcc@marino.st>
  31
  32 #include <locale>
  33 #include <cstring>
  34 #include <cstdlib>  // For MB_CUR_MAX
  35 #include <climits>  // For MB_LEN_MAX
  36
  37 namespace std _GLIBCXX_VISIBILITY(default)
  38 {
  39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  40
  41   // Specializations.
  42 #ifdef _GLIBCXX_USE_WCHAR_T
  43   codecvt_base::result
  44   codecvt<wchar_t, char, mbstate_t>::
  45   do_out(state_type& __state, const intern_type* __from,
  46          const intern_type* __from_end, const intern_type*& __from_next,
  47          extern_type* __to, extern_type* __to_end,
  48          extern_type*& __to_next) const
  49   {
  50     result __ret = ok;
  51     state_type __tmp_state(__state);
  52
  53     __c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
  54
  55     // wcsnrtombs is *very* fast but stops if encounters NUL characters:
  56     // in case we fall back to wcrtomb and then continue, in a loop.
  57     // NB: wcsnrtombs is a GNU extension
  58     for (__from_next = __from, __to_next = __to;
  59          __from_next < __from_end && __to_next < __to_end
  60          && __ret == ok;)
  61       {
  62         const intern_type* __from_chunk_end = wmemchr(__from_next, L'\0',
  63                                                       __from_end - __from_next);
  64         if (!__from_chunk_end)
  65           __from_chunk_end = __from_end;
  66
  67         __from = __from_next;
  68         const size_t __conv = wcsnrtombs(__to_next, &__from_next,
  69                                          __from_chunk_end - __from_next,
  70                                          __to_end - __to_next, &__state);
  71         if (__conv == static_cast<size_t>(-1))
  72           {
  73             // In case of error, in order to stop at the exact place we
  74             // have to start again from the beginning with a series of
  75             // wcrtomb.
  76             for (; __from < __from_next; ++__from)
  77               __to_next += wcrtomb(__to_next, *__from, &__tmp_state);
  78             __state = __tmp_state;
  79             __ret = error;
  80           }
  81         else if (__from_next && __from_next < __from_chunk_end)
  82           {
  83             __to_next += __conv;
  84             __ret = partial;
  85           }
  86         else
  87           {
  88             __from_next = __from_chunk_end;
  89             __to_next += __conv;
  90           }
  91
  92         if (__from_next < __from_end && __ret == ok)
  93           {
  94             extern_type __buf[MB_LEN_MAX];
  95             __tmp_state = __state;
  96             const size_t __conv2 = wcrtomb(__buf, *__from_next, &__tmp_state);
  97             if (__conv2 > static_cast<size_t>(__to_end - __to_next))
  98               __ret = partial;
  99             else
 100               {
 101                 memcpy(__to_next, __buf, __conv2);
 102                 __state = __tmp_state;
 103                 __to_next += __conv2;
 104                 ++__from_next;
 105               }
 106           }
 107       }
 108
 109     uselocale((locale_t)__old);
 110
 111     return __ret;
 112   }
 113
 114   codecvt_base::result
 115   codecvt<wchar_t, char, mbstate_t>::
 116   do_in(state_type& __state, const extern_type* __from,
 117         const extern_type* __from_end, const extern_type*& __from_next,
 118         intern_type* __to, intern_type* __to_end,
 119         intern_type*& __to_next) const
 120   {
 121     result __ret = ok;
 122     state_type __tmp_state(__state);
 123
 124     __c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
 125
 126     // mbsnrtowcs is *very* fast but stops if encounters NUL characters:
 127     // in case we store a L'\0' and then continue, in a loop.
 128     // NB: mbsnrtowcs is a GNU extension
 129     for (__from_next = __from, __to_next = __to;
 130          __from_next < __from_end && __to_next < __to_end
 131          && __ret == ok;)
 132       {
 133         const extern_type* __from_chunk_end;
 134         __from_chunk_end = static_cast<const extern_type*>(memchr(__from_next, '\0',
 135                                                                   __from_end
 136                                                                   - __from_next));
 137         if (!__from_chunk_end)
 138           __from_chunk_end = __from_end;
 139
 140         __from = __from_next;
 141         size_t __conv = mbsnrtowcs(__to_next, &__from_next,
 142                                    __from_chunk_end - __from_next,
 143                                    __to_end - __to_next, &__state);
 144         if (__conv == static_cast<size_t>(-1))
 145           {
 146             // In case of error, in order to stop at the exact place we
 147             // have to start again from the beginning with a series of
 148             // mbrtowc.
 149             for (;; ++__to_next, __from += __conv)
 150               {
 151                 __conv = mbrtowc(__to_next, __from, __from_end - __from,
 152                                  &__tmp_state);
 153                 if (__conv == static_cast<size_t>(-1)
 154                     || __conv == static_cast<size_t>(-2))
 155                   break;
 156               }
 157             __from_next = __from;
 158             __state = __tmp_state;
 159             __ret = error;
 160           }
 161         else if (__from_next && __from_next < __from_chunk_end)
 162           {
 163             // It is unclear what to return in this case (see DR 382).
 164             __to_next += __conv;
 165             __ret = partial;
 166           }
 167         else
 168           {
 169             __from_next = __from_chunk_end;
 170             __to_next += __conv;
 171           }
 172
 173         if (__from_next < __from_end && __ret == ok)
 174           {
 175             if (__to_next < __to_end)
 176               {
 177                 // XXX Probably wrong for stateful encodings
 178                 __tmp_state = __state;
 179                 ++__from_next;
 180                 *__to_next++ = L'\0';
 181               }
 182             else
 183               __ret = partial;
 184           }
 185       }
 186
 187     uselocale((locale_t)__old);
 188
 189     return __ret;
 190   }
 191
 192   int
 193   codecvt<wchar_t, char, mbstate_t>::
 194   do_encoding() const throw()
 195   {
 196     // XXX This implementation assumes that the encoding is
 197     // stateless and is either single-byte or variable-width.
 198     int __ret = 0;
 199     __c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
 200     if (MB_CUR_MAX == 1)
 201       __ret = 1;
 202     uselocale((locale_t)__old);
 203     return __ret;
 204   }
 205
 206   int
 207   codecvt<wchar_t, char, mbstate_t>::
 208   do_max_length() const throw()
 209   {
 210     __c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
 211     // XXX Probably wrong for stateful encodings.
 212     int __ret = MB_CUR_MAX;
 213     uselocale((locale_t)__old);
 214     return __ret;
 215   }
 216
 217   int
 218   codecvt<wchar_t, char, mbstate_t>::
 219   do_length(state_type& __state, const extern_type* __from,
 220             const extern_type* __end, size_t __max) const
 221   {
 222     int __ret = 0;
 223     state_type __tmp_state(__state);
 224
 225     __c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
 226
 227     // mbsnrtowcs is *very* fast but stops if encounters NUL characters:
 228     // in case we advance past it and then continue, in a loop.
 229     // NB: mbsnrtowcs is a GNU extension
 230
 231     // A dummy internal buffer is needed in order for mbsnrtocws to consider
 232     // its fourth parameter (it wouldn't with NULL as first parameter).
 233     wchar_t* __to = static_cast<wchar_t*>(__builtin_alloca(sizeof(wchar_t)
 234                                                            * __max));
 235     while (__from < __end && __max)
 236       {
 237         const extern_type* __from_chunk_end;
 238         __from_chunk_end = static_cast<const extern_type*>(memchr(__from, '\0',
 239                                                                   __end
 240                                                                   - __from));
 241         if (!__from_chunk_end)
 242           __from_chunk_end = __end;
 243
 244         const extern_type* __tmp_from = __from;
 245         size_t __conv = mbsnrtowcs(__to, &__from,
 246                                    __from_chunk_end - __from,
 247                                    __max, &__state);
 248         if (__conv == static_cast<size_t>(-1))
 249           {
 250             // In case of error, in order to stop at the exact place we
 251             // have to start again from the beginning with a series of
 252             // mbrtowc.
 253             for (__from = __tmp_from;; __from += __conv)
 254               {
 255                 __conv = mbrtowc(0, __from, __end - __from,
 256                                  &__tmp_state);
 257                 if (__conv == static_cast<size_t>(-1)
 258                     || __conv == static_cast<size_t>(-2))
 259                   break;
 260               }
 261             __state = __tmp_state;
 262             __ret += __from - __tmp_from;
 263             break;
 264           }
 265         if (!__from)
 266           __from = __from_chunk_end;
 267
 268         __ret += __from - __tmp_from;
 269         __max -= __conv;
 270
 271         if (__from < __end && __max)
 272           {
 273             // XXX Probably wrong for stateful encodings
 274             __tmp_state = __state;
 275             ++__from;
 276             ++__ret;
 277             --__max;
 278           }
 279       }
 280
 281     uselocale((locale_t)__old);
 282
 283     return __ret;
 284   }
 285 #endif
 286
 287 _GLIBCXX_END_NAMESPACE_VERSION
 288 } // namespace